Document Detail


A critical period of ventricular fibrillation more susceptible to defibrillation: real-time waveform analysis using a single ECG lead.
MedLine Citation:
PMID:  8848389     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Previous studies have suggested that variations in the underlying ventricular fibrillation (VF) waveform may be one of the factors responsible for the probabilistic nature of defibrillation. The heart appeared to be more susceptible to defibrillation at higher absolute VF voltages (AVFV). This study investigated in an open-chest canine model (n = 8), a newly developed system that analyzed the VF waveform in real-time, instantaneously determined the time to shock, and immediately delivered a fixed low energy DC shock. A two parameter tracking technique using a running long-term and short-term AVFV average was devised to automatically identify a high voltage peak area of the VF waveform, which has been hypothesized to represent a critical period susceptible to defibrillation. Using a DC shock estimated at the 50% success level, the performance using this technique in 58 defibrillation trials was compared to the performance of the conventional method of shocking at a fixed time (random shock method) in 62 trials. Patch size, electrode location, and discharge voltage were kept constant while VF duration, transmyocardial resistance (TMR), energy delivered, and AVFV at the point of shock were measured. Shock energy and current, TMR, and VF duration were similar with both shock methods. A significantly higher AVFV was observed for trials performed with the peak shock method (0.66 +/- 0.02 mV) as compared to trials performed with the random shock method (0.25 +/- 0.09 mV) (P < 0.003). Using lead II as the only sensing lead, the success rate was increased in 6 of 8 dogs (75%) with the new method. One animal showed identical performance, and one animal a worse performance. The overall increase in success rate was 24% using a single ECG lead (range 0%-100%; P < 0.04). Our data document that using this algorithm a period of high VF voltage can be detected in real-time. The improved success in the majority of animals supports the hypothesis that a critical period susceptible to defibrillation exists during VF. However, the high AVFV detected using a single ECG lead did not translate to an improved success rate in all animals. This suggests that other factors in addition to the VF voltage measured on a single lead of the ECG are important in characterizing this critical period.
Authors:
P W Hsia; S Frerk; C A Allen; R M Wise; N M Cohen; R J Damiano
Related Documents :
2654439 - Cardiovascular circulatory adjustments and renal function in acute heart failure.
16257069 - Electric shock: cardiac effects relative to non fatal injuries and post-mortem findings...
8575009 - Myocardial gi alpha-protein levels in patients with hypertensive cardiac hypertrophy, i...
10750759 - Autopsy findings in early and late postoperative death after partial left ventriculectomy.
16878049 - Meningococcal purpura fulminans treated with medicinal leeches.
9127409 - Limitations of the algorithm to reconfirm ventricular fibrillation in a third-generatio...
12453549 - Heart failure in primary care: qualitative study of current management and perceived ob...
7226589 - Ventricular septal rupture detected by cross-sectional echocardiography.
15276499 - Comparison of bilateral thoracic artery grafting with percutaneous coronary interventio...
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Pacing and clinical electrophysiology : PACE     Volume:  19     ISSN:  0147-8389     ISO Abbreviation:  Pacing Clin Electrophysiol     Publication Date:  1996 Apr 
Date Detail:
Created Date:  1996-10-24     Completed Date:  1996-10-24     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7803944     Medline TA:  Pacing Clin Electrophysiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  418-30     Citation Subset:  IM    
Affiliation:
Department of Biomedical Engineering, Medical College of Virginia, Virginia Commonwealth University, Richmond, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Algorithms
Animals
Defibrillators, Implantable
Dogs
Electric Countershock / methods*
Electrocardiography / methods*
Female
Male
Random Allocation
Signal Processing, Computer-Assisted*
Ventricular Fibrillation / diagnosis,  physiopathology,  therapy*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Effect of beta adrenergic receptor blockade on cardiac autonomic tone in patients with chronic stabl...
Next Document:  Ventricular fibrillation induction using nonsynchronized low energy external shock during rapid vent...